Public Thesis Defense of Marty Kinnaer - IMCN

Hybrid chemo-enzymatic heterogeneous catalysts for chiral alcohol production by Marty Kinnaer -

Vendredi 11 septembre 2026 à 15h00 - Auditoire A03 SCES - Place des Sciences, 2 - 1348 Louvain-la-Neuve -

The asymmetric synthesis of chiral alcohols is of central importance to the pharmaceutical industry, where the two enantiomers of a compound may differ profoundly in their biological activity. This thesis investigates the design and synthesis of hybrid chemo-enzymatic heterogeneous catalysts (HCEHCs) – single, recoverable solids co-hosting an inorganic catalyst and an enzyme – as a route to producing such alcohols through intensified, one-pot cascade reactions aligned with the principles of green chemistry.
A preliminary chapter explores the integration of enzymatic glucose isomerization with the acid-catalyzed dehydration of fructose to 5-(hydroxymethyl)furfural within a single material. A range of solid acid catalysts was synthesized, characterized, and evaluated under milder conditions than typical literature on the subject. Conflicting temperature and pH requirements of the catalytic partners could not be reconciled; nevertheless, the study establishes compatibility criteria for pairing chemical and enzymatic catalysts that inform the system choices in subsequent chapters. 
The principal system couples the unspecific peroxygenase PaDa-I with gold-palladium nanoparticles. Using an "enzyme-in-a-cage" strategy, the biocatalyst was immobilized as cross-linked aggregates within hollow, spray-dried supraparticles of AuPd-decorated TS-1 zeolite. The resulting bifunctional solid generates H2O2 in situ from H2 and O2 and consumes it for the enantioselective hydroxylation of ethylbenzene to (R)-1-phenylethanol (ee = 97.7 %) under mild conditions, without enzyme leaching; confocal microscopy localized the active enzyme inside the microspheres, and the catalyst was recovered and reused by filtration. Two intensification steps were then pursued by spray-drying: aerosol-assisted impregnation was shown to deposit AuPd nanoparticles directly on TS-1 and P25 TiO2, affording smaller, more intimately alloyed bimetallic particles and higher H2O2 productivity than conventional wet impregnation. Then, a one-pot assembly method was used to combine PaDa-I and AuPd/TiO2 in a single spray-drying step, with chitosan-rich cross-linked aggregates providing enzyme protection.
A second, complementary system addresses asymmetric ketone reduction. Horse liver alcohol dehydrogenase and the cofactor-regenerating complex [Cp*RhCl2]2 – mutually deactivating in homogeneous solution – were co-immobilized on a bipyridine-rich periodic mesoporous organosilica (HLADH/Rh@PMO). The material reduced 4-phenyl-2-butanone to (S)-4-phenyl-2-butanol with concurrent regeneration of NADH from formate.
Collectively, this work establishes several viable architectures for value-added HCEHCs, demonstrating their application to both oxidative and reductive chiral-alcohol synthesis and offering outlooks on future hybrid catalysts development.

Jury members :

Prof. Damien Debecker (UCLouvain) (Supervisor)
Prof. Evelyne Van Ruymbeke (UCLouvain) (Chairperson)
Prof. Tom Leyssens (UCLouvain) (Secretary)
Prof. Pascal Van der Noot (UGent, Belg.)
Prof. Frank Hollmann (TUDelft, NL.)

Pay attention : the public defense of Marty Kinnaer will also take place in the form of a videoconference